Efficacy Of Root Canal Irrigants Research Articles

Anti-biofilm efficacy of root canal irrigants against in-situ Enterococcus faecalis biofilms in root canals, isthmuses and dentinal tubules

ObjectiveTo investigate the anti-biofilm efficacy of root canal irrigants in canal spaces, isthmi and dentinal tubules of root canals ex vivo. MethodsFifty-one single-rooted premolars, each containing an isthmus, were instrumented, autoclaved and inoculated with Enterococcus faecalis for 4 weeks. One specimen was sectioned for bacteria-specific staining to confirm the presence of biofilms using light microscopiy. The remaining specimens were randomly divided to five groups: (1) 0.9% NaCl, (2) SilverSol/H2O2, (3) HYBENX, (4) QMix 2 in1, (5) 6% NaOCl. Bacterial sampling was performed before (S1) and after (S2) canal irrigation. Diluted bacteria suspension was cultured for 48 h for counting the colony forming units (CFU). Percentages of dead bacteria and biofilm thickness were evaluated by confocal laser scanning microscopy (CLSM). Metabolic activity, lactic acid and polysaccharide synthesis of E. faecalis derived from S2 samples were analysed. ResultsThe percentages of dead bacteria were significantly affected by the factor “irrigant” (p < 0.001) and the factor “location” (p = 0.017). The percentages of dead bacteria in the isthmi and canals were both in the ordor: NaCl < SilverSol/H2O2 < HYBENX < QMix 2 in1 < NaOCl (p < 0.05). Only 6% NaOCl disrupted biofilms and significantly reduced their thickness. The CFU, metabolic activity, polysaccharide and lactic acid production of E. faecalis were all reduced by the disinfecting solutions. ConclusionsSilverSol/H2O2 and HYBENX were less adept than QMix 2 in1 at killing biofilm bacteria in root canals. None of these antibacterial irrigants were effective, compared with 6% NaOCl, in disrupting biofilms. Clinical significanceThere is advantage in using HYBENX or QMix 2 in1 to kill intratubular bacteria biofilms because of their capability in removing the inorganic component of the smear layer. SilverSol/H2O2 requires extra time to eradicate intratubular biofilms upon removal of the organic and inorganic components of the smear layer by other root canal irrigants.

Cleaning Efficacy of Root Canal Irrigation with Positive and Negative Pressure System.

Introduction:The purpose of this study was to analyze the differences between irrigant replacement in the positive and negative pressure irrigation systems regarding root canal cleaning efficacy. Methods and Materials:A total of 27 extracted single-root mandibular premolars with 18-20 mm root canal length were decoronated and equally divided into three groups (n=9) based on the irrigation system used: positive irrigation with side-vented needle as the control group (C), positive irrigation with an open-ended needle as the first group (T1) and negative irrigation as the second group (T2). The root canals were irrigated with 2.5% NaOCl between each instrumentation, followed by a final irrigation with 5 mL of sterile distilled water. The irrigation replacements were monitored by means of computational fluid dynamic (CFD), while a scanning electrone microscope (SEM) was used to observe the smear layers and plug evaluations after the teeth had been sectioned longitudinally and buccolingually halves subsequently cut in apical third area. The result was analyzed using the Kruskal Wallis, Mann Whitney and Spearman correlation tests. The level of significance was set at 0.05. Result:Irrigant replacement in the negative pressure irrigation system tends to produce a greater effect in reaching the apical end compared to in the positive pressure irrigation system. This resulted in significantly superior smear layer removal in the apical third area (P<0.05). Conclusion: The irrigation solution exchange of the negative pressure irrigation system is more capable of reaching the apical end compared to the positive pressure irrigation system, resulting in a higher sanitation level in the apical third of the root canal.

Effectiveness of Different Disinfection Protocols on the Reduction of Bacteria in Enterococcus faecalis Biofilm in Teeth with Large Root Canals

IntroductionThis study compared the effectiveness of different disinfection protocols in reducing bacteria in an Enterococcus faecalis biofilm in teeth with large root canals. MethodsFifty-five roots were prepared from human mandibular premolars with large single root canals, and 50 roots were infected with E. faecalis for 21 days. Four roots were observed using scanning electron microscopy to verify biofilm formation. The remaining specimens were assigned into 5 experimental groups and a sterile control group: mechanical instrumentation using files size 60–90 and 2.5% sodium hypochlorite (NaOCl) (MI-N), irrigation with 2.5% NaOCl (IR-N), irrigation with 2.5% NaOCl using intermittent passive ultrasonic irrigation (PUI-N), irrigation with normal saline, and no intervention (initial). After root canal disinfection, dentin specimens were collected for microbial analysis. Mean colony forming units were determined and compared between groups using 1-way analysis of variance. ResultsThe lowest number of intracanal bacteria (24.5 colony-forming units/mL) was recovered from the MI-N group followed by the PUI-N and IR-N groups. The irrigation with normal saline group did not show a significant reduction compared with the initial group. However, there were significant differences between groups (P < .01). The remaining bacteria in the PUI-N group was 4.5-fold lower compared with the IR-N group; however, it was 1862-fold higher compared with the MI-N group. ConclusionsMI-N was the most effective method to disinfect large root canals. Although ultrasonic activation enhanced the efficacy of root canal irrigation, it could not substitute for mechanical instrumentation even in large root canals with unlimited irrigant access to the apical portion.

Comparison of the Antimicrobial Efficacy of Irrigation Using the EndoVac to Endodontic Needle Delivery

Introduction The purpose of this investigation was to compare the antimicrobial efficacy of root canal irrigation with the EndoVac (Discus Dental, Culver City, CA) to endodontic needle irrigation in the apical 5 mm of root canals infected with Enterococcus faecalis. Methods Bilaterally matched, extracted human teeth were sterilized and inoculated with E. faecalis. Specimens in the EndoVac group were irrigated using the EndoVac system, whereas those in the needle group were irrigated with a 30-G side-vented needle. After chemomechanical preparation, the apical 5 mm of the roots were removed, frozen in liquid nitrogen, and pulverized to expose E. faecalis in dentinal tubules or other morphologic irregularities. The number of colony forming units (cfus) of E. faecalis per mg dentin was determined. Results The EndoVac Group had a mean of 31.6 cfu/mg, whereas the needle group had a mean of 157 cfu/mg. This represents a bacterial reduction of 99.7% in group A and 98.8% in group B when compared with positive controls. Conclusion Although there were fewer cfu/mg when using the EndoVac, there was not a statistically significant difference between the EndoVac and needle groups.

The Influence of Canal Curvature on the Mechanical Efficacy of Root Canal Irrigation In Vitro Using Real-Time Imaging of Bioluminescent Bacteria

There are no quantitative data on the mechanical efficacy of irrigation in the removal of bacteria from curved canals. This study quantitatively analyzed the effects of root canal curvature and preparation size on the mechanical efficacy of irrigation using 33 mandibular single-rooted bicuspids allocated to groups according to root canal curvatures, group 1 (straight) 4 to 8 degrees, group 2 (intermediate curvature) 15 to 19 degrees, and group 3 (greatest curvature) 24 to 28 degrees. Teeth were sequentially instrumented to sizes 27/.04, 36/.04, and 46/.04 using a crown-down technique. Suspensions of the bioluminescent reporter strain Pseudomonas fluorescens 5RL (1.5 × 10 6 cells) were inoculated into canals of sterilized teeth after each sequential instrumentation. Canals were irrigated with 6 ml of irrigant delivered 1 mm from working length using a 30-gauge needle. Remaining bacteria were quantified using real-time bioluminescent imaging. Irrigation was significantly less effective in 24 to 28 degrees curvature canals prepared to size 27/.04 compared to 46/.04 (p < 0.007, repeated-measures ANOVA).

Comparative Evaluation of Endodontic Irrigants against Enterococcus faecalis Biofilms

The aim of this study was to compare the efficacy of root canal irrigants against E. faecalis biofilms using a novel in vitro testing system. Biofilms grown in a flow cell system were submerged in test irrigants for either 1 or 5 minutes. Statistical analysis revealed a significant relationship between test agent and percentage kill of the biofilm bacteria ( P < 0.05). No statistically significant relationship between time and percentage kill was found. The percentage kill of the biofilm bacteria was: 6% NaOCl (>99.99%), 1% NaOCl (99.78%), Smear Clear™ (78.06%), 2% chlorhexidine (60.49%), REDTA (26.99%), and BioPure™ MTAD™ (16.08%). Post-hoc analysis showed a significant difference between 1% and 6% NaOCl, and all other agents including Smear Clear™, 2% chlorhexidine, REDTA, and BioPure™ MTAD™ ( P < 0.05). Within the parameters of this study, both 1% NaOCl and 6% NaOCl were more efficient in eliminating E. faecalis biofilm than the other solutions tested.

The Influence of Preparation Size on the Mechanical Efficacy of Root Canal Irrigation In Vitro

This study tested the hypothesis that the mechanical efficacy of irrigation in reducing intracanal bacteria is dependent on canal preparation size. Root canals of 30 extracted permanent cuspids were prepared consecutively to sizes 36, 60, and 77 at working length (WL) using ProFile 0.04 taper Series-29 files. Smear layer was removed and teeth autoclaved following completion of each instrumentation sequence. Root canals were inoculated with a 15-mul suspension (1x10 cells) of Pseudomonas fluorescens 5RL, a salicylate-inducible bioluminescent reporter strain. Bioluminescence was measured before inoculation (background), after inoculation and after irrigation with 6 ml of irrigant delivered 1 mm from WL using a 28G safety-ended needle. The percentage of bacteria remaining following irrigation was 26.95+/-9.71%, 10.46+/-5.87%, and 10.64+/-6.01% for sizes 36, 60, and 77, respectively (p<0.001; repeated-measures ANOVA), with no difference between sizes 60 and 77 (p>0.05; Tukeys). Irrigation 1 mm from WL was significantly less effective in canals prepared to size 36.

Antimicrobial efficacy of root canal irrigants and medicaments on different phenotypes of Enterococcus faecalis

Antimicrobial efficacy of root canal irrigants and medicaments on different phenotypes of Enterococcus faecalis